Cell handover method and device

Abstract

Embodiments of the present application relate to the technical field of communications, and provide a cell handover method and a device. The method comprises: when determining to hand over a terminal device to a second cell, sending a cell handover request to a second access network device; receiving a handover request confirmation message sent by the second access network device, wherein the handover request confirmation message comprises a scheduling request resource, and the scheduling request resource comprises a resource used for sending a scheduling request on a PUCCH; and sending a first message to the terminal device, wherein the first message is used for instructing the terminal device to hand over to the second cell, and the first message comprises the scheduling request resource and parameter information of the second access network device. The terminal device can apply for an uplink grant from the second access network device on the PUCCH after cell handover, so as to send, to the second access network device on the basis of the uplink grant, a message indicating completion of the cell handover, thereby reducing large signaling overhead of a communication system during cell handover, and avoiding waste of PUSCH resources.

Description

Method and device for cell handover

[0001] The present application claims priority from the Chinese patent application No. 202411312145.5 filed on September 20, 2024, and entitled "Method and device for cell handover", the content of which is incorporated herein by reference in its entirety. TECHNICAL FIELD

[0002] The present application relates to the field of communication technology, in particular to a method and device for cell handover. BACKGROUND

[0003] One important component of the field of communication systems is satellite communication. In the scenario of satellite communication, due to the rapid movement of satellites, user equipment (UE) needs to frequently switch between different satellite cells to ensure the continuity of services.

[0004] However, in the above switching process, based on the current cell handover procedure, there is a problem of large signaling overhead of the communication system. SUMMARY

[0005] Embodiments of the present application provide a method and device for cell handover, which are applied to the field of communication technology. The method and device can reduce the problem of large signaling overhead of the communication system in the cell handover process, and can also avoid the waste of Physical Uplink Shared Channel (PUSCH) resources.

[0006] To achieve the above-mentioned purpose, embodiments of the present application adopt the following technical solutions:

[0007] In a first aspect, the embodiments of the present application provide a method for cell handover. The method can be executed by a network device deployed on a satellite, such as a first access network device including a first cell deployed on a first satellite, or can also be executed by a component (such as a chip or circuit) configured in the first access network device. The present application does not limit this.

[0008] For example, the method comprises: when it is determined to switch the terminal device to a second cell, sending a cell switching request to a second access network device, the terminal device accessing a first cell, the second access network device being deployed on a second satellite, the second access network device comprising the second cell, the terminal device being located within a signal coverage range of the second cell; receiving a switching request confirmation message sent by the second access network device, the switching request confirmation message comprising scheduling request resources, the scheduling request resources comprising resources for sending a scheduling request on a physical uplink control channel (PUCCH); and sending a first message to the terminal device, the first message being used to instruct the terminal device to switch to the second cell, the first message comprising the scheduling request resources and parameter information of the second access network device, the parameter information being used for the terminal device to access the second cell.

[0009] In this way, after receiving the cell switching request, the second access network device allocates resources for the terminal device to send a scheduling request on a PUCCH, so that the terminal device can subsequently access the second access network device and apply for an uplink grant by sending a scheduling request on the PUCCH, and then send a message indicating that the cell switching is completed to the second access network device according to the uplink grant. In this process, the resources allocated in advance by the second access network device are resources on the PUCCH, and since the resources on the PUCCH are common channel resources, even if the time when the terminal device completes the cell switching cannot be predicted and the resources on the PUCCH are allocated in advance, there will be no waste of resources. Based on this, the terminal device can send a scheduling request on the PUCCH to apply for an uplink grant after accessing the second access network device, so that the uplink grant allocated by the second access network device for the terminal device can be used in time by the terminal device, and the terminal device can send a message indicating that the cell switching is completed on a corresponding PUSCH resource according to the uplink grant, thereby avoiding the PUSCH resources configured by the uplink grant from being wasted. Moreover, since the cell switching is not performed by using a random access manner, there will be no problem of large signaling overhead of the communication system when multiple terminal devices switch cells.

[0010] In combination with the first aspect, in a possible implementation manner, the first message is a radio resource control (RRC) reconfiguration message.

[0011] In this way, the terminal device can be instructed to switch cells by using the RRC reconfiguration message, and the parameter information of the second access network device and the scheduling request resources can be carried by the RRC message, so that no additional message is needed to carry the related information, and the cell switching efficiency is improved.

[0012] In a possible implementation manner of the first aspect, before sending the cell switching request to the second access network device, the method further includes: detecting that the signal quality of the terminal device is less than a preset threshold; and determining to switch the terminal device to the second cell.

[0013] In this way, the access network device, such as the first access network device, can determine whether to switch the cell of the terminal device according to the signal quality of the connected terminal device, so as to timely instruct the terminal device to switch the cell when the signal of the terminal device is poor, thereby ensuring the network communication quality of the terminal device.

[0014] In a possible implementation manner of the first aspect, before sending the cell switching request to the second access network device, the method further includes: predicting that the terminal device will leave the coverage range of the first cell within a preset time period according to the relative moving track and the relative moving speed of the terminal device within the coverage range of the first cell; and determining to switch the terminal device to the second cell.

[0015] In this way, in the satellite communication scenario, with the movement of the satellite, the access network device deployed on the satellite can predict the time when the terminal device leaves the cell by the relative moving track and the relative moving speed of the connected terminal device within the coverage range of the cell moving with the satellite, so as to timely switch the cell of the terminal device when the terminal device is about to leave (i.e., leave within a preset time period), thereby ensuring the network communication quality of the terminal device.

[0016] In a possible implementation manner of the first aspect, before determining to switch the terminal device to the second cell, the method further includes: determining that a neighboring cell of the first cell is the second cell.

[0017] In this way, when it is determined that the cell of the terminal device needs to be switched, the terminal device can be switched to the neighboring cell of the currently accessed cell of the terminal device, so as to ensure that the switched cell of the terminal device is the cell covering the terminal device.

[0018] In a possible implementation manner of the first aspect, before determining to switch the terminal device to the second cell, the method further includes: determining, according to ephemeris information, that a satellite neighboring to the first satellite and later arriving at the position of the terminal device is a second satellite; and determining to switch the terminal device to the second cell includes: determining to switch the terminal device to a second cell included in a second access network device deployed on the second satellite.

[0019] In this way, in the satellite communication scenario, with the movement of the satellite, the access network device deployed on the satellite can determine the satellite neighboring to the satellite and later arriving at the position of the terminal device according to the ephemeris information, so as to switch the terminal device to the cell corresponding to the access network device deployed on the determined satellite when the cell of the terminal device needs to be switched, thereby ensuring that the switched cell of the terminal device is the cell covering the terminal device.

[0020] In a second aspect, an embodiment of the present application provides a method for cell switching. The method can be performed by a network device deployed on a satellite, such as a second access network device including a second cell deployed on a second satellite, or a component (for example, a chip or a circuit) configured in the second access network device. The present application does not limit this.

[0021] For example, the method includes: receiving a cell switching request sent by a first access network device, the first access network device being deployed on a first satellite, the first access network device including a first cell; allocating a scheduling request resource for a terminal device, the scheduling request resource including a resource for sending a scheduling request on a PUCCH, the terminal device accessing the first cell and being located in a signal coverage range of the second cell; sending a switching request confirmation message to the first access network device, the switching request confirmation message including the scheduling request resource; receiving a scheduling request sent by the terminal device, the scheduling request being used for applying for an uplink grant, the scheduling request being sent by the terminal device on the PUCCH according to the scheduling request resource; sending an uplink grant to the terminal device on a physical downlink control channel (PDCCH); and receiving a second message sent by the terminal device according to the uplink grant, the second message being used for indicating that the terminal device completes cell switching.

[0022] In this way, after receiving the cell switching request, the second access network device allocates a resource for the terminal device to send a scheduling request on the PUCCH, so that the terminal device accesses the second access network device and then applies for an uplink grant through the scheduling request on the PUCCH, and then sends a message indicating that the cell switching is completed to the second access network device according to the uplink grant. In this process, the resource allocated in advance by the second access network device is the resource on the PUCCH, and since the resource on the PUCCH is a common channel resource, even if the time when the terminal device completes the cell switching cannot be predicted and the resource on the PUCCH is allocated in advance, there is no waste of resources. Based on this, the terminal device can send a scheduling request on the PUCCH to apply for an uplink grant after accessing the second access network device, so that the uplink grant allocated by the second access network device for the terminal device can be used in time by the terminal device, and the terminal device sends a message indicating that the cell switching is completed on the corresponding PUSCH resource according to the uplink grant, thereby avoiding the waste of the PUSCH related resource configured by the uplink grant. Moreover, since the cell switching is not performed in the random access manner, there is no problem of large signaling overhead of the communication system when multiple terminal devices switch cells.

[0023] In a possible implementation manner of the first aspect, the second message is an RRC reconfiguration complete message.

[0024] In this way, the terminal device can be instructed to complete cell switching by the RRC reconfiguration complete message, and the second access network device can determine that the terminal device has completed cell switching according to the message.

[0025] In a third aspect, an embodiment of the present application provides a cell switching method. The method can be executed by a terminal device, or can also be executed by a component (for example, a chip or a circuit) configured in the terminal device. The present application does not limit this.

[0026] For example, the method includes: receiving a first message sent by a first access network device, the first access network device being deployed on a first satellite, the first access network device including a first cell, the terminal device being accessed in the first cell, the first message being used to instruct the terminal device to switch to a second cell, the first message including scheduling request resource and parameter information of a second access network device, the parameter information being used for the terminal device to access the second cell, the scheduling request resource including resource used to send a scheduling request on a PUCCH, the second access network device being deployed on a second satellite, the second access network device including the second cell, the terminal device being located in a signal coverage range of the second cell; accessing the second cell according to the first message; sending a scheduling request to the second access network device on the PUCCH according to the scheduling request resource, the scheduling request being used to apply for an uplink grant; receiving an uplink grant sent by the second access network device, the uplink grant being sent by the second access network device on a PDCCH; and sending a second message to the second access network device according to the uplink grant, the second message being used to instruct the terminal device to complete cell switching.

[0027] Thus, the second access network device allocates resources for the terminal device to send a scheduling request on a PUCCH after receiving the cell switching request, so that the terminal device accesses the second access network device and applies for an uplink grant by sending a scheduling request on the PUCCH, and then sends a message indicating completion of cell switching to the second access network device according to the uplink grant. In this process, the resources allocated in advance by the second access network device are resources on the PUCCH, and since the resources on the PUCCH are common channel resources, even if the time when the terminal device completes cell switching cannot be predicted and the resources on the PUCCH are allocated in advance, there will be no waste of resources. Based on this, the terminal device can send a scheduling request on the PUCCH to apply for an uplink grant after accessing the second access network device, so that the uplink grant allocated by the second access network device for the terminal device can be used in time by the terminal device, and the terminal device sends a message indicating completion of cell switching on the corresponding PUSCH resource according to the uplink grant, thereby avoiding waste of PUSCH resources configured by the uplink grant. Moreover, since cell switching is not performed using random access, there is no problem of large signaling overhead of the communication system when multiple terminal devices switch cells.

[0028] In a possible implementation of the first aspect, the first message is an RRC reconfiguration message.

[0029] Thus, the terminal device can be instructed to perform cell switching by the RRC reconfiguration message, and the parameter information of the second access network device and the scheduling request resources can be carried by the RRC message, so that no additional message is needed to carry the related information, and the efficiency of cell switching is improved.

[0030] In a possible implementation of the first aspect, the second message is an RRC reconfiguration complete message.

[0031] Thus, the terminal device can be instructed to complete cell switching by the RRC reconfiguration complete message, and the second access network device can determine that the terminal device has completed cell switching according to the message.

[0032] In a fourth aspect, an embodiment of the present application provides a communication apparatus, including various modules or units for performing the method in the first aspect and any possible implementation manner of the first aspect.

[0033] In a fifth aspect, an embodiment of the present application provides a communication apparatus, including various modules or units for performing the method in the second aspect and any possible implementation manner of the second aspect.

[0034] In a sixth aspect, an embodiment of the present application provides a communication apparatus, including various modules or units for performing the method in the third aspect and any possible implementation manner of the third aspect.

[0035] In a seventh aspect, an embodiment of the present application provides a communication apparatus, including a processor. The processor is coupled to a memory and is configured to execute instructions in the memory to implement the method in the first aspect and any possible implementation of the first aspect. Optionally, the apparatus further includes the memory. Optionally, the apparatus further includes a communication interface, and the processor is coupled to the communication interface.

[0036] In an implementation form, the communication apparatus is a network device, such as the first access network device. In this case, the communication interface can be a transceiver, or an input / output interface.

[0037] In another implementation form, the communication apparatus is a chip configured in the network device, such as the first access network device. In this case, the communication interface can be an input / output interface.

[0038] Optionally, the transceiver can be a transceiver circuit. Optionally, the input / output interface can be an input / output circuit.

[0039] In an eighth aspect, a communication apparatus is provided, including a processor. The processor is coupled to a memory and is configured to execute instructions in the memory to implement the method in the second aspect and any possible implementation of the second aspect.

[0040] Optionally, the apparatus further includes the memory. Optionally, the apparatus further includes a communication interface, and the processor is coupled to the communication interface.

[0041] In an implementation form, the communication apparatus is a network device, such as the second access network device. In this case, the communication interface can be a transceiver, or an input / output interface.

[0042] In another implementation form, the communication apparatus is a chip configured in the network device, such as the second access network device. In this case, the communication interface can be an input / output interface.

[0043] Optionally, the transceiver can be a transceiver circuit. Optionally, the input / output interface can be an input / output circuit.

[0044] In a ninth aspect, a communication apparatus is provided, including a processor. The processor is coupled to a memory and is configured to execute instructions in the memory to implement the method in the third aspect and any possible implementation of the third aspect.

[0045] Optionally, the apparatus further includes the memory. Optionally, the apparatus further includes a communication interface, and the processor is coupled to the communication interface.

[0046] In an implementation form, the communication apparatus is a terminal device. In this case, the communication interface can be a transceiver, or an input / output interface.

[0047] In another implementation, the communication device is a chip configured in the terminal device. In this case, the communication interface can be an input / output interface.

[0048] Optionally, the transceiver can be a transceiver circuit. Optionally, the input / output interface can be an input / output circuit.

[0049] In the tenth aspect, a processor is provided, which includes an input circuit, an output circuit and a processing circuit. The processing circuit is configured to receive a signal through the input circuit and transmit a signal through the output circuit, so that the processor executes the method in the first aspect or the second aspect or the third aspect, or any possible implementation manner of the first aspect or the second aspect or the third aspect.

[0050] In the implementation process, the processor can be one or more chips, the input circuit can be an input pin, the output circuit can be an output pin, and the processing circuit can be a transistor, a gate circuit, a flip-flop and various logic circuits, etc. The input signal received by the input circuit can be received and input by, for example but not limited to, a receiver, the output signal output by the output circuit can be output to and transmitted by, for example but not limited to, a transmitter, and the input circuit and the output circuit can be the same circuit which is used as the input circuit and the output circuit at different times. The embodiments of the present application do not limit the specific implementation manner of the processor and various circuits.

[0051] In the eleventh aspect, a processing device is provided, which includes a processor and a memory. The processor is configured to read instructions stored in the memory, and can receive a signal through a receiver and transmit a signal through a transmitter, so as to execute the method in the first aspect or the second aspect or the third aspect, or any possible implementation manner of the first aspect or the second aspect or the third aspect.

[0052] Optionally, the processor is one or more, and the memory is one or more.

[0053] Optionally, the memory can be integrated with the processor, or the memory and the processor are separately arranged.

[0054] In the implementation process, the memory can be a non-transitory memory, for example, a read only memory (ROM), which can be integrated with the processor on the same chip, or can be separately arranged on different chips. The embodiments of the present application do not limit the type of memory and the arrangement manner of the memory and the processor.

[0055] It should be understood that the relevant data interaction process, for example, sending indication information, can be a process in which the processor outputs indication information, and receiving capability information can be a process in which the processor receives input capability information. Specifically, the data output by the processor can be output to a transmitter, and the input data received by the processor can come from a receiver. The transmitter and the receiver can be collectively referred to as a transceiver.

[0056] The processing device in the above eleventh aspect can be one or more chips. The processor in the processing device can be implemented by hardware or software. When implemented by hardware, the processor can be a logic circuit, an integrated circuit, or the like; when implemented by software, the processor can be a general-purpose processor, which is implemented by reading software code stored in a memory. The memory can be integrated in the processor or exist independently outside the processor.

[0057] In a twelfth aspect, an embodiment of the present application provides a network device, including a processor, a memory, and a transceiver. The transceiver is configured to transceive data. The memory is configured to store code instructions. The processor is configured to run the code instructions. The processor, when executing the code instructions stored in the memory, is configured to instruct the network device to perform the method described in the above first aspect or the second aspect and any possible implementation manner of the first aspect or the second aspect.

[0058] In a thirteenth aspect, an embodiment of the present application provides a terminal device, including a processor, a memory, and a transceiver. The transceiver is configured to transceive data. The memory is configured to store code instructions. The processor is configured to run the code instructions. The processor, when executing the code instructions stored in the memory, is configured to instruct the terminal device to perform the method described in the above third aspect and any possible implementation manner of the third aspect.

[0059] In a fourteenth aspect, an embodiment of the present application provides a computer-readable storage medium, which stores a computer program or instructions. When the computer program or instructions run on a computer, the computer is caused to perform the method described in the above first aspect or the second aspect or the third aspect, and any possible implementation manner of the first aspect or the second aspect or the third aspect.

[0060] In a fifteenth aspect, an embodiment of the present application provides a chip or a chip system, which includes at least one processor and a communication interface. The communication interface and the at least one processor are interconnected through a line. The at least one processor is configured to run a computer program or instructions to perform the method in the first aspect or the second aspect or the third aspect, and any possible implementation manner of the first aspect or the second aspect or the third aspect. The communication interface in the chip can be an input / output interface, a pin, or a circuit, etc.

[0061] In a sixteenth aspect, an embodiment of the present application provides a computer program product including a computer program, which, when executed on a computer, causes the computer to perform the method of the first aspect or the second aspect or the third aspect, and any possible implementation manner of the first aspect or the second aspect or the third aspect.

[0062] It should be understood that the fourth aspect and the seventh aspect of the present application correspond to the technical solution of the first aspect of the present application, the fifth aspect and the eighth aspect of the present application correspond to the technical solution of the second aspect of the present application, the sixth aspect, the ninth aspect and the thirteenth aspect of the present application correspond to the technical solution of the third aspect of the present application, the twelfth aspect of the present application corresponds to the technical solution of the first aspect or the second aspect of the present application, and the tenth aspect, the eleventh aspect, the fourteenth aspect to the sixteenth aspect of the present application correspond to the technical solution of the first aspect or the second aspect or the third aspect of the present application. The beneficial effects obtained by each aspect and the corresponding possible implementation manners are similar, and will not be described in detail. BRIEF DESCRIPTION OF DRAWINGS

[0063] FIG. 1 is a schematic diagram of a satellite communication scenario provided by an embodiment of the present application;

[0064] FIG. 2 is a schematic diagram of a network architecture of a satellite communication system provided by an embodiment of the present application;

[0065] FIG. 3 is a schematic diagram of a flow of a method of an existing cell handover provided by an embodiment of the present application;

[0066] FIG. 4 is a schematic diagram of a flow of another method of an existing cell handover provided by an embodiment of the present application;

[0067] FIG. 5 is a schematic diagram of a flow of another method of an existing cell handover provided by an embodiment of the present application;

[0068] FIG. 6 is a schematic diagram of a flow of a method of a cell handover provided by an embodiment of the present application;

[0069] FIG. 7 is a schematic block diagram of a communication apparatus 700 provided by an embodiment of the present application;

[0070] FIG. 8 is a schematic diagram of a structure of a terminal device 800 provided by an embodiment of the present application;

[0071] FIG. 9 is a schematic diagram of a structure of a network device provided by an embodiment of the present application. DETAILED DESCRIPTION

[0072] The technical solutions in the embodiments of the present application will be described below with reference to the drawings in the embodiments of the present application. In the description of the present application, unless otherwise specified, " / " represents an "or" relationship between the objects before and after the " / ", for example, A / B can represent A or B; in the present application, "and / or" is only a description of the relationship between the associated objects, which means that there can be three relationships, for example, A and / or B, which can represent the following three cases: A exists alone, A and B exist together, and B exists alone, where A and B can be singular or plural. In addition, in the description of the present application, unless otherwise specified, "multiple" means two or more than two. "At least one of the following" or similar expressions means any combination of the items, including any combination of single or multiple items. For example, at least one of a, b, or c can represent a, b, c, a-b, a-c, b-c, or a-b-c, where a, b, and c can be single or multiple. In addition, in order to clearly describe the technical solutions of the embodiments of the present application, in the embodiments of the present application, "first", "second", and the like are used to distinguish the same items or similar items with basically the same function and effect. Those skilled in the art can understand that "first", "second", and the like do not limit the quantity and execution order, and "first", "second", and the like do not necessarily mean different. At the same time, in the embodiments of the present application, "exemplary" or "for example" means to serve as an example, illustration or description. Any embodiment or design scheme described as "exemplary" or "for example" in the embodiments of the present application should not be interpreted as more preferred or more advantageous than other embodiments or design schemes. Rather, "exemplary" or "for example" is used to present the relevant concept in a specific manner, for understanding.

[0073] In addition, the network architecture and service scenarios described in the embodiments of the present application are used to more clearly illustrate the technical solutions of the embodiments of the present application, and do not constitute a limitation on the technical solutions provided by the embodiments of the present application. Those skilled in the art can know that, with the evolution of network architecture and the appearance of new service scenarios, the technical solutions provided by the embodiments of the present application are also applicable to similar technical problems.

[0074] With the continuous development of communication technology, an important part of the communication field at present is satellite communication. In the satellite communication scenario, due to the rapid movement of the satellite, the user equipment (user equipment, UE) needs to frequently switch between different satellite cells to ensure the continuity of the service.

[0075] For example, FIG. 1 shows a schematic diagram of a satellite communication scenario provided by an embodiment of the present application. As shown in FIG. 1, the scenario includes a satellite 101 and a satellite 102. As shown in (a) of FIG. 1, at a first time, a cell of the satellite 101 covers a location where a terminal device 103 is located, and a cell of the satellite 102 does not cover the location where the terminal device 103 is located. As the satellites move, the cell coverage area of the satellite 101 gradually moves away from the location where the terminal device 103 is located, and the cell coverage area of the satellite 102 gradually moves closer to the location where the terminal device 103 is located. Thus, at a second time, as shown in (b) of FIG. 1, the terminal device 103 is located at an edge of the cell coverage area of the satellite 101 and is located in the cell coverage area of the satellite 102. At this time, in order to maintain service continuity, the terminal device needs to be handed over from the cell of the satellite 101 to the cell of the satellite 102, so as to subsequently communicate through the satellite 102.

[0076] In the embodiments of the present application, the terminal device 103 can include various handheld devices, vehicle-mounted devices, wearable devices, computing devices, or other processing devices connected to a wireless modem.

[0077] For example, the terminal device 103 can be a mobile station (MS), a subscriber unit, a user equipment (UE), a cellular phone, a smart phone, a wireless data card, a personal digital assistant (PDA) computer, a tablet computer, a wireless modem, a handset, a laptop computer, a machine type communication (MTC) terminal, or the like.

[0078] The satellite 101 and the satellite 102 can be satellites in which access network devices (such as base stations) are deployed.

[0079] It should be understood that in a satellite communication scenario, the cell coverage range of a single satellite can reach hundreds of thousands of square kilometers, but to cover the entire area, hundreds or even thousands of satellites are still needed for networking coverage.

[0080] It should be noted that the present application belongs to the category of satellite communication, and the members of the 3rd Generation Partnership Project (3GPP) integrate satellite communication and 5G technology and propose a typical network application architecture. The foregoing satellite communication scenario can be implemented based on the network application architecture.

[0081] By way of example, FIG. 2 is a schematic diagram of a network architecture of a satellite communication system provided by an embodiment of the present application. As shown in FIG. 2, a terminal device on the ground accesses a 5G new air interface network, a 5G access network device (such as a 5G base station) is deployed on a satellite, and is connected to a core network on the ground through a wireless link. At the same time, there is a wireless link between satellites to complete signaling interaction and user data transmission between base stations. The various network elements in FIG. 2 and their interfaces are described as follows:

[0082] Terminal device: a device supporting the 5G new air interface, typically a mobile device such as a mobile phone, a pad, etc. It can access the satellite network through the air interface and initiate a call, access the Internet, etc.

[0083] 5G base station: mainly provides wireless access services, schedules wireless resources to the accessed terminal device, and provides reliable wireless transmission protocols and data encryption protocols, etc.

[0084] 5G core network: user access control, mobility management, session management, user security authentication, charging, etc. It is composed of multiple functional units and can be divided into control plane and data plane functional entities. The access and mobility management unit (Access and Mobility Management Function, AMF) is responsible for user access management, security authentication, and mobility management. The user plane unit (User Plane Function, UPF) is responsible for managing the transmission of user plane data, traffic statistics, etc. The session management unit (Session Management Function, SMF) is mainly responsible for interaction with the separated data plane.

[0085] Ground station: responsible for forwarding signaling and service data between the satellite base station and the 5G core network.

[0086] 5G new air interface: wireless link between the terminal and the base station.

[0087] Xn interface: interface between 5G base stations, mainly used for signaling interaction such as handover.

[0088] NG interface: interface between 5G base stations and 5G core network.

[0089] Generally, when a terminal device switches from a source cell to a target cell, the terminal device needs to perform a random access process to the target cell.

[0090] Specifically, FIG. 3 shows a flowchart of a method for existing cell switching provided by an embodiment of the present application.

[0091] As shown in FIG. 3, when the source base station determines that the cell of the terminal device needs to be switched, the following S301-S305 can be included.

[0092] S301, the source base station sends a cell switching request to the target base station.

[0093] S302, the target base station sends a handover request acknowledgement message to the source base station according to the cell switching request.

[0094] The handover request acknowledgement message can include cell access related information such as a preamble sequence of a non-contention based random access channel (RACH).

[0095] S303, the source base station sends a radio resource control (RRC) reconfiguration message to the terminal device.

[0096] The RRC reconfiguration message can include the aforementioned cell access related information such as the preamble sequence of the non-contention based random access channel (RACH). The RRC reconfiguration message can be used to instruct the terminal device to switch the cell to the target base station.

[0097] S304, the terminal device initiates a non-contention random access to the target base station according to the RRC reconfiguration message, to switch the cell.

[0098] S305, after switching the cell, the terminal device sends an RRC reconfiguration complete message to the target base station.

[0099] The RRC reconfiguration complete message can be used to indicate that the cell switching is complete.

[0100] It should be noted that the detailed steps of the above cell switching can refer to the description in the related art, and will not be repeated here.

[0101] It should be understood that when the terminal device switches the cell by random access, a certain preamble sequence and other resources are needed, and since the coverage of the satellite base station is large, there are many terminal devices served by the satellite base station. Therefore, in the aforementioned satellite communication scenario, there may not be enough resources to support many terminal devices switching the cell at the same time. Moreover, when many terminal devices switch the cell at the same time, it can also cause excessive RACH signaling overhead.

[0102] Therefore, at present, in the satellite communication scenario, a cell switching scheme based on RACH-less is proposed to solve the above problems.

[0103] For example, FIG. 4 shows a flowchart of another existing cell switching method provided by an embodiment of the present application.

[0104] As shown in FIG. 4, when the source base station determines that the cell of the terminal device needs to be switched, the following S401-S406 can be included.

[0105] S401, the source base station sends a cell switching request to the target base station.

[0106] S402, the target base station and the source base station negotiate uplink authorization, and allocate uplink authorization for the terminal device.

[0107] S403, the target base station sends a handover request acknowledgement message to the source base station.

[0108] The allocated uplink authorization can be carried in the handover request acknowledgement message.

[0109] S404, the source base station sends an RRC reconfiguration message to the terminal device.

[0110] The RRC reconfiguration message can include the allocated uplink authorization.

[0111] S405, the terminal device performs cell switching according to the RRC reconfiguration message and accesses the target base station.

[0112] S406, after the cell switching is completed, the terminal device sends an RRC reconfiguration complete message to the target base station according to the uplink authorization.

[0113] It should be noted that the detailed steps of the above cell switching can refer to the description in the related art, and will not be repeated here.

[0114] It should be understood that when the terminal device switches the cell by the above method, in order to enable the terminal device to send the RRC reconfiguration complete message, the target base station needs to negotiate the uplink authorization in advance when the source base station sends the cell switching request, so as to allocate the uplink authorization for the terminal device in advance. This will cause the target base station to allocate the uplink authorization in advance due to the inability to accurately estimate the cell switching completion time of the terminal device under the source base station, that is, the allocated physical uplink shared channel (PUSCH) resource is wasted.

[0115] Of course, another cell switching scheme based on RACH-less has also been proposed. For example, FIG. 5 shows a flowchart of another existing cell switching method provided by an embodiment of the present application.

[0116] As shown in FIG. 5, when the source base station determines that the cell of the terminal device needs to be switched, the following S501-S506 can be included.

[0117] S501, the source base station sends a cell switching request to the target base station.

[0118] S502, the target base station sends a switching request confirmation message to the source base station.

[0119] S503, the source base station sends an RRC reconfiguration message to the terminal device.

[0120] S504, the target base station sends an allocated uplink grant to the terminal device on a physical downlink control channel (PDCCH).

[0121] S505, the terminal device performs cell switching according to the RRC reconfiguration message and accesses the target base station.

[0122] S506, after the terminal device completes the cell switching, the terminal device sends an RRC reconfiguration completion message to the target base station according to the received uplink grant.

[0123] It should be noted that the detailed steps of the above cell switching can refer to the description in the related art, and will not be repeated here.

[0124] It should be understood that when the terminal device switches the cell in the above manner, in order to enable the terminal device to send the RRC reconfiguration completion message, the target base station needs to allocate an uplink grant for the terminal device in advance and issue it to the terminal device. This will cause the target base station to waste the allocated uplink grant, i.e., the allocated physical uplink shared channel (PUSCH) resource, due to the inability to accurately estimate the cell switching completion time of the terminal device under the source base station.

[0125] Therefore, based on the foregoing various existing cell switching methods, the embodiments of the present application provide a cell switching method, which can reduce the problem of large signaling overhead of the communication system in the cell switching process, and also can avoid the waste of PUSCH resources.

[0126] For example, in a satellite communication scenario, the first access network device is a first base station deployed on a first satellite, the second access network device is a second base station deployed on a second satellite, and the terminal device accesses a first cell included in the first access network device and is located at the edge of the signal coverage range of the first cell, and the terminal device is also located within the signal coverage range of a second cell included in the second access network device. Taking the case of switching the terminal device from the first cell to the second cell as an example, FIG. 6 is a flowchart of a cell switching method provided by an embodiment of the present application. As shown in FIG. 6, the method can include the following S601-S608.

[0127] S601, when it is determined to switch the terminal device to the second cell, the first access network device sends a cell switching request to the second access network device.

[0128] The access network device can perform network detection on each terminal device accessing the cell of the access network device, so that when the communication signal quality of the terminal device is detected to drop to a preset threshold, the access network device can initiate cell switching of the terminal device. Alternatively, the access network device can also predict each terminal device accessing the cell of the access network device, and when it is predicted that the terminal device will leave the coverage range of the current cell after a preset time, the access network device can initiate cell switching of the terminal device.

[0129] For example, in the present example, the terminal device accesses the first cell of the first access network device and is located at the edge of the first cell, so the communication signal quality between the terminal device and the first access network device is poor. At this time, when it is determined to switch the terminal device to the second cell, the first access network device can perform network detection on the terminal device, and the detected signal quality is below the preset threshold (may be less than the preset threshold, or can be less than or equal to the preset threshold, which can be configured according to the actual situation in implementation, and is not limited here), so it is determined that the terminal device needs to be switched to the second cell; alternatively, the first access network device can predict the relative movement of the terminal device according to the relative movement trajectory and relative movement speed of the terminal device in the coverage range of the first cell of the first access network device, so as to predict that the terminal device will leave the coverage range of the current cell within a preset time length, and thus determine that the terminal device needs to be switched to the second cell.

[0130] For example, in a satellite communication scenario, the access network device determines which cell to switch the terminal device to, which can be determined according to the neighbor cell or ephemeris information. For example, in this example, the first access network device can determine to switch the terminal device to the second cell of the second access network device based on the neighbor cell of the first cell of the first access network device being the second cell of the second access network device. Alternatively, the first access network device can determine, according to the ephemeris information, a second satellite adjacent to the first satellite where the first access network device is located and later arriving at the location where the terminal device is located, and thus determine to switch the terminal device to the second cell of the second access network device deployed on the second satellite.

[0131] The cell handover request sent by the first access network device can be used to indicate that the second access network device needs to switch the terminal device to the second cell of the second access network device. In the cell handover request, the parameter information of the terminal device (such as the frequency band and modulation mode supported by the terminal device) can be carried, so that the second access network device allocates corresponding resources (such as scheduling request resources) for the terminal device. Of course, the cell handover request can also include other information, which is not limited here, and can refer to the implementation of the cell handover request in related technologies.

[0132] As a possible implementation, the first access network device can use the Xn interface to send the cell handover request through the inter-satellite link or the feeder link. Of course, in the embodiments of the present application, how to send the cell handover request is not limited and can also be configured according to actual conditions.

[0133] S602, the second access network device allocates scheduling request resources for the terminal device.

[0134] The scheduling request resource can be a resource used to send a scheduling request on a physical uplink control channel (PUCCH). Through this resource, the terminal device can subsequently apply for an uplink grant (UL Grant) to the second access network device through the PUCCH. When the second access network device allocates scheduling request resources for the terminal device, it can allocate PUCCH resources for the terminal device, and the PUCCH resources include the scheduling request resources. Alternatively, the second access network device can also specifically allocate the scheduling request resources for the terminal device, which is not limited here.

[0135] Of course, in the embodiments of the present application, after receiving the cell handover request, the second access network device can also allocate other resources for cell handover for the terminal device, such as core network resources, which are not limited here.

[0136] S603. The second access network device sends a handover request acknowledgement message to the first access network device.

[0137] In the handover request acknowledgement message, a scheduling request resource allocated for the terminal device is carried.

[0138] As a possible implementation, the second access network device can use an Xn interface to send the scheduling request resource through an inter-satellite link or a feeder link. Of course, in the embodiments of the present application, how to send the scheduling request resource to the first access network device is not limited, and can also be configured according to actual conditions.

[0139] S604. The first access network device sends a first message to the terminal device.

[0140] The first message can be used to instruct the terminal device to switch to the second cell, and the first message can include parameter information of the second access network device and a scheduling request resource configured by the second access network device for the terminal device.

[0141] As an example, the first message can be an RRC reconfiguration message. The RRC reconfiguration message can include parameter information of the second access network device and a scheduling request resource configured by the second access network device for the terminal device.

[0142] For example, the parameter information of the second access network device is used for the terminal device to access the second cell, and can include information in a system information block (SIB) of the second access network device for cell switching and access. For example, the parameter information can include one or more of the following information: PLMN identity of the cell of the second access network device, cell selection information, cell reselection parameters, time division duplex (TDD) configuration information, system information window length, cell reselection information, neighbor relation, cell access restriction, cell-specific reference signal configuration, orbit parameters of the satellite where the second access network device is located, signal beam configuration, and the like. Through the parameter information, the terminal device can facilitate access to the second access network device.

[0143] S605. The terminal device accesses the second cell according to the first message.

[0144] For example, the terminal device can perform downlink synchronization and calculate an uplink timing advance (TA) according to the parameter information of the second access network device in combination with ephemeris information, and access the second cell.

[0145] After the terminal device accesses to the second cell, a message indicating that the cell switching is completed needs to be sent to the second access network device, so as to complete the cell switching process and then perform normal communication. Therefore, the terminal device needs to request a related resource for sending the message. That is, the following steps are performed.

[0146] S606, the terminal device sends a scheduling request to the second access network device on the PUCCH according to the scheduling request resource.

[0147] The scheduling request can be used to apply for an uplink grant. The terminal device can send the message indicating that the cell switching is completed on the corresponding PUSCH resource through the uplink grant. Of course, the scheduling request can also be used to inform the second access network device that it has accessed the second access network device (i.e. has performed cell switching) and is waiting for the scheduling of the second access network device.

[0148] Since the first access network device sends the first message indicating switching the cell to the terminal device, the first message includes the scheduling request resource allocated by the second access network device. The scheduling request resource is the resource for sending the scheduling request on the PUCCH, so the terminal device can send the scheduling request to the second access network device on the PUCCH according to the scheduling request resource in the first message.

[0149] S607, the second access network device sends an uplink grant to the terminal device on the PDCCH.

[0150] S608, the terminal device sends a second message to the second access network device according to the uplink grant.

[0151] The second message is used to indicate that the terminal device completes the cell switching. The second message sent according to the uplink grant can be a second message sent on the PUSCH related resource according to the uplink grant, and the PUSCH related resource can be configured by the uplink grant.

[0152] For example, the first message indicating that the terminal device performs cell switching by the first access network device is an RRC reconfiguration message, and the second message can be an RRC reconfiguration complete message.

[0153] The terminal device indicates that the cell switching has been completed through the second message, so as to facilitate the second access network device to determine that the terminal device completes the cell switching, so as to subsequently perform normal communication.

[0154] Based on the method for cell switching provided in the embodiments of the present application, it can be seen that the second access network device allocates resources for the terminal device to send a scheduling request on a PUCCH after receiving a cell switching request, so that the terminal device accesses the second access network device and then applies for an uplink grant by sending a scheduling request on the PUCCH, and then sends a message indicating that cell switching is completed to the second access network device according to the uplink grant. In this process, the resources allocated by the second access network device in advance are resources on the PUCCH, and since the resources on the PUCCH are common channel resources, even if the time when the terminal device completes cell switching cannot be predicted, the resources on the PUCCH allocated in advance will not be wasted. Based on this, the terminal device can send a scheduling request on the PUCCH to apply for an uplink grant after accessing the second access network device, so that the uplink grant allocated by the second access network device for the terminal device can be used in time by the terminal device, and the terminal device sends a message indicating that cell switching is completed on the corresponding PUSCH resource according to the uplink grant, thereby avoiding the PUSCH related resources configured by the uplink grant from being wasted. Moreover, since the cell switching does not use a random access manner, there is no problem of large signaling overhead of the communication system when multiple terminal devices switch cells.

[0155] The above describes in detail the method for cell switching provided in the embodiments of the present application in combination with FIG. 6, and the apparatus provided in the embodiments of the present application will be described in detail in combination with FIG. 7.

[0156] FIG. 7 is a schematic block diagram of a communication apparatus 700 provided in the embodiments of the present application. As shown in FIG. 7, the communication apparatus 700 can include a processing unit 701 and a transceiver unit 702.

[0157] In a possible design, the communication apparatus 700 can implement operations of a corresponding first access network device in the embodiments of the method shown in FIG. 6, for example, the communication apparatus can be the first access network device, or a component configured in the first access network device, for example, a chip or a circuit.

[0158] The communication apparatus can implement corresponding operations of the first access network device in the embodiments of the method shown in FIG. 6. Each unit in the communication apparatus 700 is combined to implement corresponding procedures in the embodiments of the method shown in FIG. 6.

[0159] Specifically, the processing unit 701 of the communication apparatus 700 can be configured to determine whether to handover a terminal device to a second cell. The transceiver 702 can be configured to: send, to a second access network device, a cell handover request when it is determined to handover the terminal device to the second cell, the terminal device accesses a first cell, the second access network device comprises the second cell, and the terminal device is located in a signal coverage of the second cell; receive a handover request acknowledgement message sent by the second access network device, the handover request acknowledgement message comprises a scheduling request resource, and the scheduling request resource comprises a resource for sending a scheduling request on a PUCCH; and send a first message to the terminal device, the first message is used to instruct the terminal device to handover to the second cell, and the first message comprises the scheduling request resource and parameter information of the second access network device, the parameter information is used for the terminal device to access the second cell.

[0160] In another possible design, the communication apparatus 700 can implement operations of a corresponding second access network device in the method embodiment shown in FIG. 6. For example, the communication apparatus can be the second access network device, or a component (for example, a chip or a circuit) configured in the second access network device.

[0161] The communication apparatus can implement corresponding operations of a second access network device in the method embodiment shown in FIG. 6. Each unit in the communication apparatus 700 is combined to implement corresponding procedures in the method embodiment shown in FIG. 6.

[0162] Specifically, the transceiver 702 of the communication apparatus 700 can be configured to: receive a cell handover request sent by a first access network device, the first access network device comprises a first cell; send, to the first access network device, a handover request acknowledgement message, the handover request acknowledgement message comprises a scheduling request resource; receive a scheduling request sent by a terminal device, the scheduling request is used to apply for an uplink grant, and the scheduling request is sent by the terminal device on a PUCCH according to the scheduling request resource; and send the uplink grant to the terminal device on a PDCCH. The processing unit 701 can be configured to allocate a scheduling request resource for the terminal device, the scheduling request resource comprises a resource for sending a scheduling request on a PUCCH, the terminal device accesses the first cell, and is located in a signal coverage of a second cell.

[0163] In another possible design, the communication apparatus 700 can implement operations of a corresponding terminal device in the method embodiment shown in FIG. 6. For example, the communication apparatus can be the terminal device, or a component (for example, a chip or a circuit) configured in the terminal device.

[0164] The communication apparatus can implement corresponding operations of a terminal device in the method embodiment shown in FIG. 6. Each unit in the communication apparatus 700 is combined to implement corresponding procedures in the method embodiment shown in FIG. 6.

[0165] Specifically, the transceiver unit 702 of the communication apparatus 700 can be configured to receive a first message sent by a first access network device, the first message being used to instruct a terminal device to perform cell switching to a second cell, the first message comprising a scheduling request resource and parameter information of a second access network device, the parameter information being used for the terminal device to access the second cell, the scheduling request resource comprising a resource used to send a scheduling request on a PUCCH, the second access network device comprising the second cell, the terminal device being located in a signal coverage of the second cell; send a scheduling request to the second access network device on the PUCCH according to the scheduling request resource, the scheduling request being used to apply for an uplink grant; receive an uplink grant sent by the second access network device, the uplink grant being sent by the second access network device on a PDCCH; and send a second message to the second access network device according to the uplink grant, the second message being used to instruct the terminal device to complete the cell switching. The processing unit 701 can be configured to access the second cell according to the first message.

[0166] It should be understood that the specific process of each unit performing the corresponding steps described above has been described in detail in the method embodiments described above, and for the sake of brevity, will not be repeated here.

[0167] It should also be understood that the division of modules in the embodiments of the present application is illustrative, and is only a logical functional division. Actual implementation can have another division manner. In addition, each functional module in each embodiment of the present application can be integrated in one processor, or can be physically separated, or two or more modules can be integrated in one module.

[0168] The integrated module described above can be realized in the form of hardware or in the form of a software functional module.

[0169] It should be understood that the communication apparatus 700 can correspond to the terminal device or the network device (such as the first access network device or the second access network device) in the foregoing embodiments. The processing unit 701 in the communication apparatus 700 can correspond to the processor in the terminal device or the network device, and can invoke the instructions stored in the memory through the processor in the terminal device or the network device to realize the functions described above, such as network coding, obtaining original packets, etc. The transceiver unit can correspond to the interface in the terminal device or the network device, and can realize the functions of receiving and / or sending data described above in response to the instructions of the processor.

[0170] It should be understood that the transceiving unit 702 in the communication apparatus 700 can be implemented by a transceiver or a communication interface, for example, can correspond to the transceiver 802 in the terminal device 800 shown in FIG. 8 and the transceiver 910 in the network device 900 shown in FIG. 9. The processing unit 701 in the communication apparatus 700 can be implemented by at least one processor, for example, can correspond to the processor 801 in the terminal device 800 shown in FIG. 8 and the BBU 920 in the network device 900 shown in FIG. 9.

[0171] FIG. 8 is a structural schematic diagram of a terminal device 800 provided by an embodiment of the present application. The terminal device 800 can perform the functions of the terminal device in the above-mentioned method embodiments. As shown in FIG. 8, the terminal device 800 includes a processor 801 and a transceiver 802. Optionally, the terminal device 800 further includes a memory 803. The processor 801, the transceiver 802 and the memory 803 can communicate with each other through internal connection paths to transfer control and / or data signals. The memory 803 is configured to store a computer program. The processor 801 is configured to invoke and run the computer program stored in the memory 803 to control the transceiver 802 to transceive signals. Optionally, the terminal device 800 can further include an antenna 804 configured to send uplink data or uplink control signaling output by the transceiver 802 through wireless signals.

[0172] The processor 801 and the memory 803 can be combined into one processing apparatus. The processor 801 is configured to execute program codes stored in the memory 803 to implement the above-mentioned functions. Specifically, the memory 803 can be integrated in the processor 801 or independent of the processor 801. The processor 801 can correspond to the processing unit 701 in FIG. 7.

[0173] The transceiver 802 can correspond to the transceiving unit 702 in FIG. 7. The transceiver 802 can include a receiver (or receiver circuit) and a transmitter (or transmitter circuit). The receiver is configured to receive signals, and the transmitter is configured to transmit signals.

[0174] It should be understood that the terminal device 800 shown in FIG. 8 can implement each process involving the terminal device in the method embodiment shown in FIG. 6. The operations and / or functions of each module in the terminal device 800 are respectively implemented to implement the corresponding processes in the above-mentioned method embodiments. For details, refer to the description in the above-mentioned method embodiments, and the detailed description is appropriately omitted here to avoid repetition.

[0175] The processor 801 can be configured to perform the actions described in the foregoing method embodiments and implemented by the terminal device, and the transceiver 802 can be configured to perform the actions described in the foregoing method embodiments and performed by the terminal device in sending or receiving information to or from the network device (e.g., the first access network device or the second access network device). For details, refer to the descriptions in the foregoing method embodiments, which will not be repeated here.

[0176] Optionally, the terminal device 800 can further include a power supply 805 configured to supply power to various devices or circuits in the terminal device.

[0177] In addition, the terminal device 800 can further include one or more of an input unit 806, a display unit 807, an audio circuit 808, a camera 809, and a sensor 810, and the audio circuit can further include a speaker 811 and a microphone 812.

[0178] FIG. 9 is a structural schematic diagram of a network device provided by the embodiments of the present application, for example, a base station / CU or the like. Taking the base station as an example, the base station 900 can perform the functions of the network device (e.g., the first access network device or the second access network device) in the foregoing method embodiments. As shown in FIG. 9, the base station 900 can include one or more radio frequency units, such as a remote radio unit (RRU) 910 and one or more baseband units (BBU) (also referred to as a distributed unit (DU)) 920. The RRU 910 can be referred to as a transceiver unit, which corresponds to the transceiver unit 702 in FIG. 7. Optionally, the RRU 910 can also be referred to as a transceiver, a transceiver circuit, or a transceiver, and the like, which can include at least one antenna 911 and a radio frequency unit 912. Optionally, the radio frequency unit 912 can include a receiving unit and a sending unit, and the receiving unit can correspond to a receiver (or a receiver, a receiving circuit), and the sending unit can correspond to a transmitter (or a transmitter, a transmitting circuit).

[0179] The RRU 910 part is mainly used for the transceiving of radio frequency signals and the conversion between radio frequency signals and baseband signals, for example, for sending indication information to the terminal device. The BBU 920 part is mainly used for baseband processing and controlling the base station, and the like. The RRU 910 and the BBU 920 can be physically arranged together or physically separated, that is, a distributed base station.

[0180] The BBU 920 is a control center of the base station, which can also be referred to as a processing unit, and can correspond to the processing unit 701 in FIG. 7. The BBU 920 is mainly configured to complete baseband processing functions, such as channel coding, multiplexing, modulation, spreading, etc. For example, the BBU (processing unit) 920 can be configured to control the base station to perform the operation procedures of the network device in the above method embodiments, for example, to generate the above scheduling request resource, etc.

[0181] In one example, the BBU 920 can be composed of one or more boards. The multiple boards can collectively support a single access mode wireless access network (such as an LTE network), or can separately support wireless access networks of different access modes (such as an LTE network, a 5G network, or other networks). The BBU 920 further includes a memory 921 and a processor 922. The memory 921 is configured to store necessary instructions and data. The processor 922 is configured to control the base station to perform necessary actions, for example, to control the base station to perform the operation procedures of the network device in the above method embodiments. The memory 921 and the processor 922 can serve one or more boards. That is, the memory and the processor can be separately arranged on each board. Alternatively, the multiple boards can share the same memory and processor. In addition, each board can further be provided with necessary circuits.

[0182] It should be understood that the base station 900 shown in FIG. 9 is capable of implementing each process involving the first access network device or the second access network device in the method embodiments shown in FIG. 6. The operations and / or functions of each module in the base station 900 are respectively configured to implement the corresponding procedures in the above method embodiments. For details, reference can be made to the description in the above method embodiments, and the detailed description is appropriately omitted here to avoid repetition.

[0183] It should be understood that the base station 900 shown in FIG. 9 is only one possible architecture of the network device, and should not constitute any limitation to the present application. The methods provided in the present application can be applicable to network devices of other architectures.

[0184] The embodiments of the present application further provide a processing device, comprising a processor and an interface; the processor is used for executing the method in the method embodiments. It should be understood that the processing device can be one or more chips. For example, the processing device can be a field programmable gate array (FPGA), can be an application specific integrated circuit (ASIC), can also be a system on chip (SoC), can also be a central processor unit (CPU), can also be a network processor (NP), can also be a digital signal processor (DSP), can also be a microcont roller unit (MCU), can also be a programmable logic device (PLD) or other integrated chip.

[0185] In the implementation process, each step of the above method can be completed by the integrated logic circuit of the hardware in the processor or the instruction in the software form. The steps of the method disclosed in the embodiments of the present application can be directly embodied as the execution completed by the hardware processor, or executed by the combination of the hardware and the software module in the processor. The software module can be located in the mature storage medium in the field, such as random access memory, flash memory, read-only memory, programmable read-only memory, electrically erasable programmable memory, register, etc. The storage medium is located in the memory, and the processor reads the information in the memory, and combines the hardware to complete the steps of the above method. To avoid repetition, it will not be described in detail here.

[0186] It should be noted that the processor in the embodiments of the present application can be an integrated circuit chip with a signal processing capability. In the implementation process, the steps of the above method embodiments can be completed by an integrated logic circuit or an instruction in the form of software in the processor. The processor described above can be a general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components. The disclosed methods, steps and logic block diagrams in the embodiments of the present application can be implemented or executed. The general-purpose processor can be a microprocessor or the processor can also be any conventional processor or the like. The steps of the method disclosed in conjunction with the embodiments of the present application can be directly embodied as a hardware code processor for execution, or a combination of hardware and software modules in the code processor for execution. The software module can be located in a random access memory, a flash memory, a read-only memory, a programmable read-only memory or an electrically erasable programmable memory, a register or other mature storage medium in the art. The storage medium is located in the storage, and the processor reads the information in the storage, and combines the hardware to complete the steps of the above method.

[0187] It can be understood that the memory in the embodiments of the present application can be a volatile memory or a non-volatile memory, or can include both volatile and non-volatile memories. Among them, the non-volatile memory can be a read-only memory (ROM), a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), an electrically EPROM (EEPROM) or a flash memory. The volatile memory can be a random access memory (RAM) used as an external cache. By way of example but not limitation, many forms of RAM are available, such as static random access memory (SRAM), dynamic random access memory (DRAM), synchronous dynamic random access memory (SDRAM), double data rate synchronous dynamic random access memory (DDR SDRAM), enhanced SDRAM (ESDRAM), synchlink DRAM (SLDRAM) and direct rambus RAM (DR RAM). It should be noted that the memory of the system and method described herein is intended to include but not limited to these and any other suitable types of memory.

[0188] According to the method provided by the embodiments of the present application, the present application further provides a computer program product, which comprises computer program codes, and when the computer program codes run on a computer, the computer executes the method performed by the terminal device or the first access network device or the second access network device in the embodiment shown in FIG. 6.

[0189] According to the method provided by the embodiments of the present application, the present application further provides a computer readable medium, which stores program codes, and when the program codes run on a computer, the computer executes the method performed by the terminal device or the first access network device or the second access network device in the embodiment shown in FIG. 6.

[0190] According to the method provided by the embodiments of the present application, the present application further provides a system, which comprises the terminal device and the first access network device and the second access network device.

[0191] In this specification, the terms "component", "module", "system" and the like are used to represent computer-related entities, hardware, a combination of hardware and software, software, or software in execution. For example, a component can be, but is not limited to, a process running on a processor, a processor, an object, an executable, a thread of execution, a program, and / or a computer.

[0192] Those skilled in the art can realize that the various illustrative logical blocks and steps described in connection with the embodiments disclosed herein can be implemented by electronic hardware, or a combination of computer software and electronic hardware. The choice of hardware or software implementation depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of the present application.

[0193] If the functions are implemented in the form of software function units and sold or used as independent products, they can be stored in a computer readable storage medium. Based on this understanding, the technical solutions of the present application essentially or the parts of the prior art that make contributions or parts of the technical solutions can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes a plurality of instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the embodiments of the present application. The aforementioned storage medium includes a U disk, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk, and various media that can store program codes.

[0194] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art can easily think of changes or replacements within the technical scope disclosed in the present application, which should be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A method of cell handover, characterized by, The method is applied to a first access network device, the first access network device is deployed on a first satellite, and the first access network device comprises a first cell. When it is determined to switch the terminal device to a second cell, a cell switching request is sent to a second access network device, the terminal device accesses the first cell, the second access network device is deployed on a second satellite, the second access network device comprises the second cell, and the terminal device is located in a signal coverage range of the second cell. A switching request confirmation message sent by the second access network device is received, the switching request confirmation message comprises scheduling request resources, and the scheduling request resources comprise resources for sending a scheduling request on a physical uplink control channel (PUCCH). A first message is sent to the terminal device, the first message is used to instruct the terminal device to switch to the second cell, the first message comprises the scheduling request resources and parameter information of the second access network device, and the parameter information is used for the terminal device to access the second cell.

2. The method of claim 1, wherein, The first message is a radio resource control (RRC) reconfiguration message.

3. The method of claim 1, wherein, Before the cell switching request is sent to the second access network device, the method further comprises: It is detected that a signal quality of the terminal device is less than a preset threshold. It is determined to switch the terminal device to the second cell.

4. The method of claim 1, wherein, Before the cell switching request is sent to the second access network device, the method further comprises: According to a relative moving track and a relative moving speed of the terminal device in the coverage range of the first cell, it is predicted that the terminal device will leave the coverage range of the first cell within a preset time length. It is determined to switch the terminal device to the second cell.

5. The method according to claim 3 or 4, characterized in that, Before the determination to switch the terminal device to the second cell, the method further comprises: It is determined that a neighboring cell of the first cell is the second cell.

6. The method according to claim 3 or 4, characterized in that, Before the determination to switch the terminal device to the second cell, the method further comprises: According to ephemeris information, it is determined that a satellite adjacent to the first satellite and later arriving at a location where the terminal device is located is the second satellite. The determination to switch the terminal device to the second cell comprises: It is determined to switch the terminal device to the second cell of the second access network device deployed on the second satellite.

7. A method of cell handover, characterized by, The method is applied to a second access network device, the second access network device is deployed on a second satellite, and the second access network device comprises a second cell. A cell switching request sent by a first access network device is received, the first access network device is deployed on a first satellite, and the first access network device comprises a first cell. Scheduling request resources are allocated for a terminal device, the scheduling request resources comprise resources for sending a scheduling request on a physical uplink control channel (PUCCH), the terminal device accesses the first cell, and is located in a signal coverage range of the second cell. A switching request confirmation message is sent to the first access network device, and the switching request confirmation message comprises the scheduling request resources. The network device receives a scheduling request sent by the terminal device, the scheduling request being used to apply for an uplink grant, and the scheduling request being sent by the terminal device on a PUCCH according to the scheduling request resource; The network device sends the uplink grant to the terminal device on a PDCCH; The network device receives a second message sent by the terminal device according to the uplink grant, the second message being used to indicate that the terminal device completes cell switching.

8. The method of claim 7, wherein, The second message is a radio resource control (RRC) reconfiguration complete message.

9. A method of cell handover, characterized by, The method is applied to a terminal device, the terminal device accesses a first cell, a first access network device includes the first cell, the first access network device is deployed on a first satellite, and the method comprises the following steps: The terminal device receives a first message sent by the first access network device, the first message being used to indicate that the terminal device switches to a second cell, the first message including a scheduling request resource and parameter information of a second access network device, the parameter information being used for the terminal device to access the second cell, the scheduling request resource including a resource used to send a scheduling request on a PUCCH, the second access network device being deployed on a second satellite, the second access network device including the second cell, and the terminal device being located in a signal coverage range of the second cell; The terminal device accesses the second cell according to the first message; The terminal device sends a scheduling request to the second access network device on the PUCCH according to the scheduling request resource, the scheduling request being used to apply for an uplink grant; The terminal device receives an uplink grant sent by the second access network device, the uplink grant being sent by the second access network device on a PDCCH; The terminal device sends a second message to the second access network device according to the uplink grant, the second message being used to indicate that the terminal device completes cell switching.

10. The method of claim 9, wherein, The first message is a radio resource control (RRC) reconfiguration message.

11. The method according to claim 9 or 10, characterized in that, The second message is a radio resource control (RRC) reconfiguration complete message.

12. A network device, comprising: The network device comprises: a processor and a memory; the memory stores computer-executed instructions; the processor executes the computer-executed instructions stored in the memory, so that the network device executes the method in any one of claims 1-6 or the method in any one of claims 7-8.

13. A terminal device, comprising: The terminal device comprises: a processor and a memory; the memory stores computer-executed instructions; the processor executes the computer-executed instructions stored in the memory, so that the terminal device executes the method in any one of claims 9-11.

14. A computer-readable storage medium, the computer-readable storage medium storing a computer program, characterized in that, The computer program is executed by the processor to implement the method in any one of claims 1-6 or the method in any one of claims 7-8 or the method in any one of claims 9-11.

15. A chip system, characterized by The network device comprises at least one processor and a communication interface, the communication interface and the at least one processor are interconnected through a line, and the at least one processor is used to run a computer program or instructions to execute the method in any one of claims 1-6 or the method in any one of claims 7-8 or the method in any one of claims 9-11.

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